Can You Prune a Southern Magnolia?

General Pruning

• Southern magnolias can be pruned under some circumstances. Pruning can improve the health of magnolias by elminating broken braches, weak branches with tight crotches or diseased portions of the tree. It can also minimize damage to life or property by getting rid of branches that interfere with power lines or obstruct sight lines near driveways, traffic signs or street corners. To enhance circulation under or around the tree, long branches can be shortened and lower branches can be removed.

Site Considerations

• Southern magnolias are large trees, reaching up to 80 feet tall and 50 feet wide. Avoid future frequent and unnecessary pruning by planting them far enough from other trees, utility lines and structures. Gardeners sometimes prune trees to help adjacent or understory plants grow. However, even with pruning, little will grow under the dense canopy of most cultivars of the Southern magnolia. This species has a pyramidal form with low-growing branches, which often bend toward and may even touch the ground.

Timing of Pruning

• Prune trees at planting to remove any weak or poorly located shoots. Also eliminate any branches that compete with the central leader, or trunk, at this time. Once established, Southern magnolia trees will produce large, showy spring flowers. Trees bloom early in the growing season and finish flowering before the beginning of June in most locations. For best results, prune trees immediately following flowering. Pruning at any other time likely will eliminate or reduce the buds forming for the next season.

Espalier Training

• An espalier is a plant that is trained to grow near a wall or other form of support. It is often used where landscape space is limited. Many types of magnolia trees, including the Southern magnolia, respond well and will flower profusely as espaliers in sunny locations. Espalier training is a high-maintenance form of pruning that must begin while magnolia trees are young and pliable. It consists of regular shortening of outward-growing leaves and removal of inward-growing shoots. Limbs are continuously bent and tied. Minor hardware is needed to attach magnolia trees to walls, but no support is necessary. Given the overall size of Southern magnolia, do not attempt this type of training near one- or two-story buildings, which are too small to support the tree.